Even taking into account the weight, some drugs have different effects in men and women. Pharmacological studies do not take sufficient account of sex to adapt the recommendations. Overview of this new war of the sexes.
Gender is a factor which pharmacologists will probably pay more attention to the future. Indeed, the effectiveness of drugs and their side effects may be expressed differently in men and women. Published in 2001, a U.S. government report noted as well that at least four of the ten drugs recently withdrawn from the market in the United States, had higher toxicity for women. In most cases, there was cardiac toxicity, causing a higher risk of fatal arrhythmias.
Torsades de pointes
The antiarrhythmic drugs may cause acute disorders of heart rhythm sometimes fatal called torsades de pointes, which occurs when the duration of ventricular contraction heart lengthens. The authors found that in 70% of cases this complication affects women, although they represent only 44% of prescriptions.
This particular risk is the fact that the duration of contraction of the ventricles is greater among them. This concept is important to know because it should lead doctors:
A prescribed preferentially to women antiarrhythmic drugs or just not acting on the duration of ventricular contraction;
Or consider starting treatment during hospitalization to detect and treat promptly any rhythm disorder.
Other drugs such as antibiotics and psychiatric medications, in particular, could also increase the risk of cardiac arrhythmias in women, says the Society for Research on Women's Health (Society for Women's Health Research - SWHR) American organization based in Washington.
Morphine most active
For other substances, are the therapeutic effects differ. This is particularly true for morphine and its derivatives, which exert analgesic effects more pronounced in women.
Some derivatives, such as substances that target kappa opioid receptors in the brain, have significant analgesic effects at certain doses in women, as they grow, however, the pain in humans.
The cause of these differences is more difficult to determine that, in animals, it is the males that respond most to morphine.
Two studies indicate that women are, however, less sensitive to products used for general anesthesia. She woke up on average a few minutes earlier than men for the same doses per kg of weight. They also tend to have more side effects.
The causes of these disparities between men and women may be hormonal, but also related to the higher proportion of fat in women, the smaller size of organs or the functioning of different enzymes involved in hepatic drug metabolism. Several studies indicate, in fact, that some of these enzymes are more active in women. It is likely that the mechanisms involved differ according to the drug.
Including women in the early trials
These few examples underscore how important it is to ensure that clinical trials before the marketing of a drug are carried taking into account the two sexes. Excluding trials for diseases specific to women or men, women are often smaller.
Above all, they are more rare in the early stages of study medication. However, these tests are called Phase 1 and 2 which are used to evaluate the safety and determine the dosage of medicines.
Moreover, in certain specialties, studies continue to affect populations primarily male. While much progress has been made in recent years, there remains a long way to go.